


3 is a Magic Number

by bumbleb_tch



Category: Miraculous Ladybug
Genre: Alternate Universe - Soulmates, F/M, Identity Reveal, Look they're making potions, OT3, Red String of Fate, The second part will be them finding their other soulmate, This is a poly fic but the first chapter is just a reveal, Triad - Freeform, it be like that, soulmate
Language: English
Status: In-Progress
Published: 2020-04-16
Updated: 2020-04-16
Packaged: 2021-03-01 17:46:41
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,818
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23691064
Author URL: https://archiveofourown.org/users/bumbleb_tch/pseuds/bumbleb_tch
Summary: She took a deep breath and forced her eyes open, first noting Chat frozen in front of her and then quickly turning to her notes to scribble down what she’d noticed so far. Marinette’s fingers tingled with restless energy, and she underscored ‘possible addictive properties’. “Chat? Status update.”The boy sputtered to life behind her, stammering a series of disjointed not-quite-words and landing on, “Uh, this?”Marinette rolled her eyes, “Ten points to Hufflepuff for clarity and precision,” She reached up to brush away her bangs with her other hand, something red drifting into her periphery. “What the hell?” Shooting up, she spun to face her partner, holding her hand up in front of her face. Two neat bows of red string were tied around her pinky, loose ends from each drifting down and away from her.One spanned the short distance between herself and Chat, nearly taut and almost glowing, a low hum emanating from it. The other tumbled to the floor, loops tangling with another string that she chased back up to Chat’s finger, the pair stretching out the window and into Paris.---Alternatively, a day testing recipes from the grimiore takes a sharp twist of fate--Currently on Hiatus
Relationships: Adrien Agreste | Chat Noir/Marinette Dupain-Cheng | Ladybug, Relationship tag will be posted once it's revealed, This IS a poly fic - Relationship, but it's a SURPRISE - Relationship
Comments: 31
Kudos: 86





	3 is a Magic Number

**Author's Note:**

> Okay so...instead of finishing one soulmate au, I wrote another
> 
> Oops. (I promise Shadow will be done soon pls don't eat me)

Marinette puttered back and forth along the table, adding ingredients to a large cauldron. She tapped her phone to check the time, frowning to see that Chat was late. It wasn’t uncommon, he sometimes had trouble escaping his civilian life, though he couldn’t tell her why exactly. But usually he was on time for their biweekly brewfest - as he had affectionately labeled it. 

When Master Fu had lost his memories and passed her the guardianship of the Miraculous, he’d also left a hard drive of the grimoire and any translations he’d managed to decode, as well as suggestions for other ability enhancing potions that he hadn’t finished working through. His biggest blessing was her newfound ownership of his old apartment. Ladybug had revealed this to Chat on their next patrol and they settled on using the space as an emergency hide-out and laboratory. 

Most of the recipes in the book were decoded, it was their uses that the guardian was struggling to decipher. Foolishly, she had suggested it would be much simpler to attempt making the potions than to try and decode a language that they had exactly zero knowledge of- in theory, anyway. 

Their transformations quickly proved to be cumbersome when it came to potion making, so the endeavor was postponed long enough for Marinette to sew a pair of regular masks to match their magical ones. They both wore simple and nondescript clothing, sweatpants and t-shirts, to not give anything away about their identities, and sent their kwamis off to have a snack away from where they worked. 

They were getting the hang of it, but it turned out that magical liquids were a tad temperamental. She’d regretted her suggestion the first time that the cauldron exploded, coating both of them with a stench that didn’t come out of her hair until the next time she cast the Cure- a solid three days later, much to her displeasure.

Just thinking about it seemed to agitate the mixture she was stirring and a large bubble popped on the surface in a way that was not at all reassuring. Marinette always struggled to learn from her mistakes and today was no different. She’d jumped to get started and now she was nearing the tricky parts.

And she had no Chat to help her. With a stomach rolling gurgle, the cauldron that she was hunched over shifted to a bile-like shade of green and erupted magnificently, dousing her face in a viscous goop. 

Marinette froze, letting the liquid drip down her skin while she took a deep breath to calm her temper. This was the first trial of the day, she couldn’t very well toss it out the window before Chat even showed up. Marinette groaned and allowed herself to stomp a little as she ducked behind a screen to wipe her face and change into a fresh shirt. Tikki looked up from where she was tucked in a cozy scarf nest hidden behind the divider, and obviously held back giggles. A heavy sigh broke through her lips as she swiped the goo away from her eyes.

Marinette balled up soaked fabric and tossed it aside, turning to dig through one of the organizers she’d brought to store supplies. Tugging out a plain grey hoodie and sliding it over her head, she rounded the screen again. Her head popped through the hole to find her partner only inches away, his inhuman eyes bright and gleaming with mischief.

She shrieked and tumbled back, tripping over her own feet and glowering up at him from the floor. “Use a door instead of a window for once in your life!” 

Marinette hadn’t mentioned it until then, but while she showed up in her civilian form and entered the apartment normally, Chat always showed up transformed and entered through the window, destranforming once he was inside. “Paris’ local catboy hopping through a window isn’t exactly incognito!”

His shoulders shook as he cackled, delighting in her irritation. “Trust me, this is more inconspicuous than if I tried to come as a civilian, Bug.” One of Chat’s eyebrows was crooked up in a dare; they both knew that was dancing a little too close to something dangerous and even Ladybug’s pride wasn’t likely to push her to risk their identities. 

So she huffed and hauled herself to her feet, shoving him a little harder than gently as she moved back to their makeshift workbench. “I’m going to pretend I didn’t hear that. Get a move on, I need your help with the timing.” 

Chat hopped to obey her without complaint, returning moments after a bright flash, adjusting his mask around his wide and now very  _ human _ eyes. 

Marinette still wasn’t used to them. She’d seen them before, when he’d been Mr. Bug for the day, but there hadn’t been much time to really take them in. Spending hours together sweating over boiling liquid left her with too much time to think about them.

Without Plagg’s effect, Chat’s eyes were just barely a shade lighter, close enough to be called twins, but missing the shadow of power that came with chaos. She tore her gaze back to the recipe and began re-adding ingredients.

“Your loyal lab assistant is here to help, Mi’lady.” Chat chirped, clearly in a much better mood than she was. “What are we testing today?”

Marinette hummed, dragging her finger down the list and double checking she had everything ready. “It’s hard to say. Master Fu scribbled a note that it was using a specific stressed version of the verb ‘to see’. He thought maybe it would enhance our vision somehow.” 

Tilting her head up, she aimed a wry smile in his direction, “Guess what the bad news is.”

The pout that crumbled his face was criminally sulky and pitiful and Marinette decided it should be banned in the city of Paris and also potentially all of Europe. But the whine that exited Chat’s mouth was a nasally imitation of Plagg, “Oh, my Lady, you summon me here by your side and I fly to assist you, only to be greeted with bad news?”

Her stare was dry and accusatory, but she knew he could see the amusement in her eyes. “You’re full of jokes now but we have to put this,” she jabbed a ladle in the direction of the cauldron, the mixture currently a sickly yellow. “In our mouths.”

Chat gaped at her, his nose wrinkling in disgust as he sniffed the brew, “What? Why not our kwamis like usual?”

A nasally but deeply indignant, “Hey!” piped from behind the divider. 

Marinette spun to glare at the screen hard enough for Plagg to feel it even if he couldn’t see it, “Stop eavesdropping, Plagg! You’re not supposed to know anything!” A quiet snicker was her only reply as her attention returned to Chat, who had the long suffering look of someone who spent most of their time with the tiny god of destruction. 

“Master Fu was very specific that this enhanced the holders, not the kwamis,” Marinette shrugged, “That makes me think it isn’t transformation based, but I’m not sure what else it could be.” She rocked back on her heels and stirred the mixture, watching it simmer to the appropriate temperature. “We’re nearing the tricky part, add these separately, but in as quick succession as you can. The book said they can’t go in at the same time, but ideally must be less than a second apart.”

Brushing her bangs away from her sweaty forehead, she scowled into the liquid, “Which is pretty fucking stupid if you ask me.” 

Chat snorted, obviously biting back a grin, “That’s some pretty harsh language coming from you, Bugaboo.”

“Don’t call me, Bugaboo!” Marinette snapped, flicking a few drops of potion in his direction. “It should turn green any second and then you have to add the peacock feather, the forget-me-not petals, and uh-, that.” Looking at the tiny vial made her stomach turn. She wasn’t usually one to be squeamish, but the recipe had called for what Master Fu translated as ‘a drop of the river of life.’ 

Chat had sliced his hand open and poured a good bit more than a drop into a vial before she could even blink. The sight had made bile rise in her throat, and the memory threatened to do the same. Despite moonlighting as superheroes, neither of them were often left with injuries that even broke the skin, something she had wondered about on more than one occasion, but eventually settled on the unsatisfactory answer that perhaps her Ladybug Luck was just holding out. 

Saving her from her own thoughts, the simmering reached its peak and swirled into the same sickening green hue that had exploded on her earlier. Marinette sidled behind Chat a little, praying they wouldn’t have a repeat performance. Chat dropped the ingredients with a seamless transition between each one, ending with the single drop of blood that fell through the air to hit the dead center of the cauldron.

The goo inside swallowed the scarlet tear, bursting into a blinding light that had her squeezing her eyes shut to protect them from the blast. She blinked away the spots in her vision, glancing down into the cauldron to find an odorless pearlescent liquid shifting inside. “Well...maybe this won’t be terrible.” 

“Shots, shots, shots.” Chat dunked two cups into the potion, passing her one and holding the other up for her to tap.

Giggling despite herself, Marinette clacked their plastic cups together and they tipped it back in sync. 

Flavor flooded her tongue, overwhelming her senses to the threshold of bliss. She couldn’t pry her eyes open long enough to see if Chat was experiencing something similar around the crashing waves of blackberries wreathed in cinnamon and drizzled with lemon custard.

Marinette wondered if perhaps it was too late to change her dream to baking and spend the rest of her life chasing this exact blend of flavors replicated anew. The high was fizzing away as quickly as it had come, melting from her tongue by the second and filling every nerve of her body with an ache for more. 

She took a deep breath and forced her eyes open, first noting Chat frozen in front of her and then quickly turning to her notes to scribble down what she’d noticed so far. Marinette’s fingers tingled with restless energy, and she underscored ‘possible addictive properties’. “Chat? Status update.”

The boy sputtered to life behind her, stammering a series of disjointed not-quite-words and landing on, “Uh, this?” 

Marinette rolled her eyes, “Ten points to Hufflepuff for clarity and precision,” She reached up to brush away her bangs with her other hand, something red drifting into her periphery. “What the hell?” Shooting up, she spun to face her partner, holding her hand up in front of her face. Two neat bows of red string were tied around her pinky, loose ends from each drifting down and away from her. 

One spanned the short distance between herself and Chat, nearly taut and almost glowing, a low hum emanating from it. The other tumbled to the floor, loops tangling with another string that she chased back up to Chat’s finger, the pair stretching out the window and into Paris.

Marinette’s eyes snapped to meet Chat’s, for once not even the slightest bit distracted by his stunning irises, as they gaped at each other. Or maybe that was ambitious of her to say. Distantly, she registered Tikki and Plagg calling from behind the screen to ask if they were okay.

“Everything’s, uh-fine!” she managed to choke out before their kwamis panicked enough to emerge and risk learning more about the grimoire than they should. 

Chat whispered a hushed, “What is this?” waving his hand about and watching the strings flutter with his actions. His pupils dilated wide enough that Marinette entertained a brief fantasy of Chat Noir chasing after the world’s largest ball of yarn. 

“I-I,” Something in her gut shifted restlessly, anxiety pouring into her veins as she confronted the implications of what was happening. “I think they’re soul threads.” She lowered her gaze back to her hand, twisting it this way and that, as if they might suddenly reveal a secret. 

As if they hadn’t already.

“C’mon, Mi’lady, save me the humiliation of having to ask a stupid question,” Chat whined, waving his threaded hand in her face.

Normally Marinette would roll her eyes and scoff at him, no doubt the reaction he was prodding for, but instead she continued to stare vacantly at her hand. “When I was small, my maman told me this legend, as a bedtime story.” She lifted her hand until it was near his, their twin bows nearly brushing with how little string was left between them. “It was a lovely idea, that every person was born with a red soul thread tied around their pinkie 

“At the other end of the thread was their soulmate, connected by fate, their perfect partner.” Marinette slid her hand away and watched the thread lengthen as though unraveling from a hidden spool. She found that with every word her voice dropped, but her resolve strengthened, beating back her anxiety.

Chat’s hand twitched to follow her retreat, but he kept silent. 

“I don’t remember hearing about having two at once though.” Frowning softly, she reached back towards him, palm up. 

An invitation.

The pause as Chat seemed to weigh and process the information was nearly painful, an oppressive weight on her chest. Carefully, as though he thought she might dissolve into smoke or snatch her hand away at the last second, Chat tucked his hand into hers, their fingers threading together as though they were two pieces of the same puzzle, finally fitting together.

It was far from the first time she had held Chat Noir’s hand. But this was the first time that her palm burned from the contact, fire spreading up her arm and into her chest, warming her from within with whispers of love and trust and  _ him.  _ An overwhelming awareness of him. 

Marinette looked up to see if Chat was as enraptured in their connection as she was, only to find he was staring pensively towards the window, or more accurately, the tangled strings disappearing through it. His profile was highlighted by the sun pouring through the window across from them and she found herself gripped with the foreign desire to trace her fingers along the planes and ridges of his face. Over and over, until she’d inscribed every minute detail on her heart. 

As if he felt her eyes, Chat turned his head and his face practically glowed as a soft smile twisted his lips, so much more gentle and vulnerable than the cheeky grins and antagonistic smirks she was used to seeing. Something bloomed inside her, a heady wave of what could only be called bliss, crashing over Marinette’s entire being, filling every crevice of her soul. 

She cringed, wondering if feeling like this was a consequence of the potion or if she’d really just buried any thoughts of her partner deep enough under her infatuation with Adrien that she’d missed her  _ soulmate  _ and it took  _ literal magic  _ to make her realize it. 

Adrien. Oh shit. 

Marinette’s eyes jumped to the threads, cycling through a million possibilities. Even Ladybug couldn’t be that lucky. A model  _ and  _ a superhero? She traced back up to Chat’s face, studying him with an intensity that seemed to make him anxious. It couldn’t be that easy. Or maybe it could. Her mind couldn’t picture Adrien and Chat  _ not  _ getting along like a house on fire. 

Adrien’s gentle and steady demeanor tempering Chat’s chaotic freedom; their sense of humor matched too, guaranteed to drive her completely out of her mind.

Chat fidgeted through the heavy silence, breaking it to blurt, “So...we have a third soulmate?”

His words startled her from her intense reverie, she sputtered a bit before managing to very casually reply, “It would seem that way. Should we follow it, you think?” 

Luckily, either he hadn’t noticed her quick descent into certain Marinette™ traits, or he was taking pity on her and ignoring it. Chat glanced from her to the window a few times, his eyes clouded with thoughts that she imagined were similar to her own. “I-I think I know who it is.” 

The unspoken, “or who I hope it is, anyway”, hung in the space between them, her lungs gasping to breath in air that suddenly seemed too thick.

“R-really?” Marinette managed, beating back the vain hope that the words Adrien Agreste might fall from Chat’s honeyed lips.

Chat’s features were earnest and open, and for a moment her nerves lifted, “You know Marinette, right?” 

Her mind went blank, every thought evaporating as if they’d been cataclysmed away. A high pitched ringing echoed in her ears and she snapped her jaw shut from where it had been gaping. “W-what?”

His hands grasped her arms gently, lifting her into a hug and twirling in a circle. “She’s one of my best friends, she’s fantastic! Kind, brave, compassionate, she’s the only girl that’s ever been able to compare to you. I know you’ll love her.”

Marinette’s anxiety skyrocketed even as his praise stroked something inside her, a self-satisfied little voice that whispered-he loves me twice. But she couldn’t hold her tongue, blurting, “It can’t be!”

Chat stilled abruptly and leaned back to look down at her, shock and surprise warring in his features. “Why not?” He bit out, voice tinged with a warning that she wasn’t sure he knew he was giving. “What’s wrong with Marinette?”

Marinette cringed, jumping to her own defense and wondering if now was really the right time to break the rules, but finding herself terrified to take the leap. “Nothing! Absolutely nothing, it’s just-”

“What, you think you know who it is? Someone  _ better  _ than Marinette?” The words were practically growled in her direction as Chat backed away from her. “Please, enlighten me, Ladybug.”

“Th-that’s not what I meant, I-” She lurched after him, hesitating to reach out but desperate to pull him back to her and soothe away the agitation she was only managing to heighten. “There’s this guy who sits in front of me in school, right? I’ve been in love with him for ages and he’s stupid and perfect and a model, and he’s never  _ seen _ me but I was hoping-”

“-that it might be him.” Chat finished, his voice sanded smooth of the edge that it contained moments prior, but still a little strained. “What’s his name, Bug?”

Marinette groaned and buried her face in her hands, confronting the unfortunate reality that she was living, in which she was confessing her long unrequited crush to her superhero partner that had just turned out to be her soulmate. “Adrien Agreste.” She mumbled into her palms.

“Adrien Agreste,” Chat parroted, a note of incredulity in his voice. 

Her head shot up and she narrowed her eyes in his direction, a fierce defense already rising in her chest, “Well, I-

His eyes blew wide and a gleeful, almost manic smile stretched across his face as he laughed,  “Bugaboo, is that who your crush has been this whole time?” His tone was playful and teasing, but she bristled all the same. “A bit famous, isn’t he?”

“It’s not like that! I know him and he’s intelligent and gentle and it’s not some silly crush, and I’ve wasted so much time it has to be him! I know it is.” Marinette clenched her fists, her pride and temper clashing to defend her choices and desires even against light jabs.

Chat sashayed towards her, his smirk looking a little too much like the one he’d make seconds before dropping a devastatingly terrible pun. “I hate to be the bearer of bad news, Mi’lady, but I’m absolutely sure that string-” He held up his hand and pointed to the string headed out the window, “-doesn’t lead to Adrien Agreste.”

His hand swooped up to cup her chin, preventing her from retreating or rebutting as he plowed on, smirk softening around the edges, “Don’t cry just yet though, cause I’m pretty sure the other one does.” 

A strangled whimper exited her throat. 

“And I’m really banking on the idea that if the reason I’m so sure Adrien isn’t at the other end of that string, is the same reason you’re so sure that Marinette isn’t either.” Chat twisted the string that connected them between his fingers, that smirk curving wickedly again, and she just knew he was enjoying watching her squirm with every word. “Am I right, Princess?”

Suddenly, it was like seeing with new eyes. Marinette’s trembling hands rose to his face, tracing along the edge of the mask she had made for him, framing painfully familiar eyes that she wanted to curse herself for not recognizing sooner. “Adrien.”

“Always by your side, Marinette.” Chat - Adrien - let his hands drift up her arms to rest over hers, sliding the mask away from his face. 

If she had any doubts, they vanished as she drank in the sight of features she’d admired a million times-on both of them-and never managed to chart the similarities. The gentle restraint that Adrien exhibited was hidden under Chat’s desperation for freedom, but was also what made him so suited to the miraculous of Destruction. 

She could  _ see  _ him. How could she have been so blind, all this time?

And then she was stumbling into his arms without a second thought, her fingers wound in his hair, and tugging him down to crash her lips into his. He gasped and Ladybug could feel him tremble against her. It was everything she’d ever imagined, like fresh rain falling on desert flowers, bursting into life anew. 

His hands tugged away her mask and she smirked, tilting her head to deepen the kiss; he thought he was so funny stressing her out like that, but they’d see who’d be laughing when she was finished with him. Breaking the kiss only once the need for air became desperate, she smiled sunnily up at his flushed face, Chat’s eyes hooded and dark.

He laughed, a hoarse, throaty chuckle that whispered danger up and down her spine as he continued to cradle her in his arms. “I have to admit, Bugaboo, if I had known that all I needed to do to win your heart was be Adrien Agreste, I would’ve swept you off your feet ages ago.”

Ladybug whacked his shoulder, burying her burning cheeks in his chest as he laughed with his entire body, his glee innocent as a child’s. “Shut up, you mangy cat! You’ve forgotten the bigger issue! If I’m-” She scanned the room out of habit before realizing her own actions and blushing furiously “-Marinette, and you’re Adrien...Who is at the end of this string?”

**Author's Note:**

> I hope y'all enjoyed it! 
> 
> Second part will come soon, don't worry 
> 
> Feel free to make a guess down below from the one very tiny hint that I left ;)


End file.
